Thursday, December 1, 2011

Tree of the Month: American Chestnut

Though today is the first of December, you have probably already heard Christmas tunes on the radio for weeks. It's hard to think of the holidays without getting that lyric about chestnuts stuck in your head. For that, you can thank the American chestnut (Castanea dentata), our December Tree of the Month.

Before the early 1900's, there were approximately 4 billion American chestnut trees in the Northeast. They stood up to 110 feet tall and provided delicious nuts for street vendors to roast and sell during winter months. But due to a fungus-related disease called chestnut blight, American chestnuts rapidly disappeared. Fortunately, chestnut blight does not kill the tree's roots, so some sprouts survived. Today there are hundreds of healthy American chestnuts in the mountains of Michigan and Pennsylvania.

Since American chestnuts are somewhat rare in D.C., finding one is a special treat! You can find two American chestnut trees on the grounds of the Smithsonian National Museum of Natural History and one that was planted in 2005 near the U.S. Department of Agriculture. More American chestnuts can be found in surrounding areas such as Glencarlyn Park and Sugarloaf Mountain.

How can you tell if you've spotted a rare American chestnut?

The leaves are simple and alternate and are usually between five and nine inches long. They are yellow-green and have sharply toothed edges.

The flowers are yellow cylindrical clusters, between four and nine inches long. They bloom between the late spring and early summer.

The edible chestnuts grow inside of prickly burs. Up to three nuts can be found in one shell. They sprout in early autumn.

The jagged edges of an American chestnut leaf. Photo credit: njheart2heart

Be mindful not to confuse the American chestnut with its non-native relative the Chinese chestnut (Castanea mollissima). Chinese chestnuts have similar characteristics, but their leaves are identifiable by their dark, glossy green color and shorter length.